Question: What temperature is calcium carbonate that had a density of 2.7?
Paraphrase: At what temperature does calcium carbonate have a density of 2.7?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q23767 p:P2054 ?s . ?s ps:P2054 ?x filter(contains(?x , '2.7')) . ?s pq:P2076 ?value}